Spring-actuated supporting device



C. W. DAVIS AND F. R. SUNDERLIN.

SPRING ACIUATED SUPPORTING EVICE.

APPLICATION FILED JUNE 6. 191B. Patented Mar. 2,I I920.

s SHEETSSHEET I.

I NV EN TOR. (Opf/.AND MZ .DA ws.

A TTORNEY.

C. W. DAVIS AND F. R. SUNDEIILIN.

SPRING ACIUATED SUPPORTING DEVICE.

APPLICATION FILED JUNE 6,1918.

Patented Mar. 2, 1920.

s SHEETS-SHEET 2.

A TTORNEY.

C. W. DAVIS AND F. R. 'SUNDERLIM sPRlNG AcIuATf-:D SUPPORTING DEVICE.

APPLICATION .FILED )UNE 6.1918.

1,332,383. Patented Mar. 2, 1920.

3 SHEETS-SHEET 3.

INVENTORS CoRTLA/vo PV, vDAV/.5. FRA/vx 'Sv/VDERL/N.

' ATTORNEY.

'll'NIlED STATES PATENT FFICE.

CORTLAN D W. DAVIS AND FRANK R. SUNDEELIN, 0F CHICAGO, ILLINOIS,ASSIGNORS TO THE MANTLE LAMP COMPANY 0F AMERICA, 0F CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS.

SPRING-ACTUATED SUPPORTING DEVICE.

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Application led .Tune 6,

To all @07mm t may concern.'

Be it known that we, CORTLAND W. DAVIS and FRANK R. SUNDERLIN, citizensof the United States, residing at Chicago, in the county of Cook andState of Illinois, have invented a new and useful Improvement in Spring-Actuated Supporting Devices, of which the following is a specification.

yThe invention relates to the kind of springactuated supporting devicewhich is commonly employed for sustaining, raising and lowering lampsand other pendent objects, and it consists, primarily, of means forpreventing premature descent of an object attached to such a device,even though its weight constitutes an overload for the spring. Thenormal load for devices of this character ranges from five to tenpounds, but by employing an added stop mechanism, the fixture may bemade to sustain a load up to its breaking point, as for instance, a loadapproximating one hundred pounds.

The device comprises a shell in which a winding drum is supported, awinding drum, a coiled spring for actuating said winding drum, a pawland ratchet locking device actuated by gravity or centrifugal force andchains attached each at one end to Said drum, and at the other end tolamp or other pendent object. The spring is, in such devices asheretofore constructed, of suiiicient strength to counter-balance thenormal load, but, in many instances, it happens that the load, beinggreater than the spring is able to sustain, operates to unwind thespring and leave the object in a lowered position.

Uur device is provided with an automatic load-sustaining stop which isinherently strong enough to carry any reasonably heavy load in excess'of that which the spring of the winding drum is able to resist. Thisload-sustaining stop, as we have shown it, consists of a pawl, the freeend of which is adapted automatically to engage any one of a series ofsomewhat closely related detents or openings (which act as ratchetteeth), unless the speed be so great that the pawl passes over itwithout opportunity to effectuate an interlocking engagement. y

The addition of such an automatic stop to the ordinary suspension devicein which are employed a spring-actuated drum and a clutch for lockingthe parts to prevent the Specification of Letters Patent.

Patented Mar. 2, 11920.

191s. serial no. 238,553.

spring from lifting' them, produces a new entity in which the liftingspring is opposed We propose to use clutches of any desired character,the essential feature being such disposition of the clutches as willenable them to act oppositely, whereby either the spring or gravity maybe eectually resisted at the will of the operator, as the 7o pendentdevice is raised or lowered.

Another feature of our device is the tapering form of the winding drumwhich is of truncated-conical shape, the object being to automaticallycause the sustaining chains of 75y the device to be alternately andclosely laid in a single layer upon the drum during the windingoperation to thereby insure uniform winding. lf the coils of the chainwere superimposed, the winding speed 8o would be variable, as will bereadily understood.

Several other features of the invention are the" means' for mounting thedrumI and its actuating spring, the means for mounting the guide rollerfor the chains, the construction of the detents for the pawl, and themeans 'for sustaining the shell or canopy of the device from and indirect Contact with an over-head support.

The several parts of the device are so designed that all except thespring and idler pulleys may each be stamped from a single piece ofsheet metal.

The details of our invention are illustrated in the accompanyingdrawing, which forms part of this specification.

Figure l is a view in elevation of the entire device, the shell thereofbeing shown in section;

Fig. 2 is a transverse vertical section, the supporting chains beingomitted;

Fig. 3 is a plan view;

Figs. 4L and 5 are,respectively, views showing the cross bar of thedevice and elements supported thereby.

A, is the shell, having' diametricallyv disposed lobes, a, extendingfrom the upper part thereof. The bottom, 0.1, of the shell is providedwith an annular groove, a2.

The drum, B, is of truncated conical form 5 and is provided with a cap,C, having a conical center, c, and a cylindrical hearing, o1. Threeintegral punched tongues, 02, constituting tie-plates and provided withintegral lugs, c3, extending through the bottom, 0*, of

`the drum, B, unite the drum and the cap. The cap is provided with.sixopenings, c5, o", the former of which are the openings from 4whichthe tongues, c2, are punched. These several openings are adapted toreceivel the l5 1free ends of the pawls with which the device isprovided as will hereinafter appear. The bottom ofthe drum is providedwith a central cylindrical bearing portion, @which is v disposed inalinement with the cylindrical bearing portion, c1.

A tube, D, .constituting an axis for the drumy extends from thecylindrical groove, a2, in the bottom of the shell, A, through thedrumandto a cross-bar, E, which is Vinount- `ed upon the shell, A. Thistube is provided with lugs, d, extended through and riveted to thecross-bar, E. The tube is ythus held securely` at bothits lower and itsupper end, to therebyconstitute a fixed axis for the drum, B. The tube,l), is madeV from a. single sheet of metal, the meeting edges of `whichare united .by a tongue, d1, and a slit, d2, the

vtonguebeing riveted at its outer end to `prevent its withdrawal. Theedges of the metal below the tongue, (Z1, are spaced apart at d3,forthe` reception of thel innerend ofthe winding spring.

F, is the winding spring the inner endof which issfolded at,f,.aroundythe ,proximate edge of the metal tube at the slot, cl3. Theouterend of the spring is bentaround one edge .ofa punched tongue, 02,.so .that the tension ofgthespring tends to vdraw .the bent end `thereofinto close engagement with said edge. Thespring is thus held inoperative relation tothe drum, without the aid ofV any added securingmeans.

VThecross-bar, E, and theshell, A, are providedwith alined openings, e,154,through which a headedfscrew, G, extends. VThis screw constitutesthe sole supporting means for the device, which is especially .desirablex because it admitsof a direct contactbetween the'shell, A, andtheceiling,thereby avoid ing the use ofy additional ,sustaining means, suchasare commonly employed in lamp .ix tures. The screw `has an ornamentalthumbpiece, g, by means of which it may be actuated, as well f. as anornamental head, g1,

which concealsthe opening in the vbottom of the shell, A. n

Thecross-bar, E, is provided with mar ginal stilfenng ribs, el, and,atits ends, with. depending lugs, e2, through the threaded pernforations, e3, of which retaining screws, e4, carried by shell, A,extend.

The cross-bar, E, carries two U-shaped members, H, between which aremounted cylindrical idlers, h, for the sustaining chains of the device.These U-shaped plates are cut away at, 71,1, to form guides for thechains, thus avoiding the necessity of providing the idlers, 7L, withgrooves. The idlers are so 4mounted relatively to these guides as toprevent the binding' of the chains as they run back and forth over theidlers. The plates, H, are secured to the crossbar, E, by integralrivetedlugs, h2.

The cross-bar also carries an angle plate, l,

,which is secured `thereto by riveted lugs, ,The angle plate, l, carriestwo oppositely extending pawls, J, each of which is provided with.a-.notchat `its end, j, said y.pawls being looselypivoted so as tobeactuated/ by gravity. One ofithese `pawls operates to prevent `the.undue operation of-,the l spring drum,

.while the other operates to prevent the pendent objectI fromdescendingtoa greaterl degree` than` isA desired. The ends of these pawls arespaced apart aproperdistance relativelytc the distances betweenftheopens ings, c5, 0G, so that only one pawl kwillbe `in engagement at onetime, through its notch, y'. The pawls, as will be seen, are so shapedthat ,theyy ride idly over the openings of the series, when moving inone direction,` and engagethe walls of saidopenings whenmovingintheopposite direction. .The holes are sufliciently small tol allowfthepawls `to pass entirely overy them ifV the winding or the unwinding ofthe chainis at all rapid, the engagementtaking place only when themotion is slow. The operator lmay `therefore,by carefully manipulatingythe pendent object, bring .either one .01?, the pawls .into action,thsdetaining theobj ect` at any,desired altitu` e.

The sustaining means for the v,pendentpbject consists oftwochains, K,both of which are .secured to the small end?9, of thedrum, Bf Thesechains, aswillbe observed, are woundalternately upon the drum in asingle layer, the ends ofthe chainsbeing extended over the idlers, @andthrough openings,y a5, in the shell, A. This ,is a superior. formofwinding, inasmuch as it insuresthe taking up` of. yequal lengths .of thesupporting chains. l

-The generalformof the shell, A,is circular, although ,it isprovidedwith the lobes, a,: for the reception .of the .1J-shaped plates,H.

The drum, B, is provided with outwardly extending. lugs, b1, punchedfrom the outer wall thereoffand theselugs operate to prevent thechains,from slidingoffthe smaller end ofthe drum. i

All the parts of .thedevice .exceptthe spring and the idlers are sodesigned as to be fashioned by stamping from sheet metal. This is adistinct advantage, inasmuch as it eliminates the time, labor andeXpense incident to the casting and the machining of the parts.

The parts are -furthermore secured together without the addition otextraneous securing devices, the screws, c4, being the only separatesecuring means with which the entire device is provided.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

1. A spring-actuated suspension device including a drum, a pendent cordadapted to unwind from said drum in a single direction, and oppositelyacting gravity clutches for respectively restraining the ruiming of saidcord to and from said drum.

2. A suspension device including oppositely acting gravity pawls, anddetents spaced to engage only one of said pawls at the one time.

3. A suspension device including oppositely acting independent pawls,and detents for said pawls spaced apart distances each unequal to thedistance between the engaging parts of said pawls.

1. A spring-actuated suspension device, including a speed-controlledload-sustaining stop, the movable element of said stop being supportedon a fixed Jinlcrum.

5. A springactuated suspension device, including a speed-controlledload-sustaining locking stop, the movable element oi" said stop beingsupported on a iixed iulcrum.

6. A spring-actuated suspension device. including an independent clutchand an independent automa-tic load-sustaining locking stop adapted tooperate in alternation with said clutch.

7. A suspension device including oppositely acting pawls, and detentsspaced apart distances each less than the distance between engagingparts ot said pawls.

S. A suspension device, having a truncated conical shaped winding drum,a plus rality of chains attached to the small end of said drum, thetaper ci said drum being such that the winding strain will force thecoils of the chains together.

9. A suspension device, including in coin- 'bination a casing, a crossbar secured to said casing, a spring-actuated winding drum, and an forsaid drum supported at its respective ends by the casing and the crossbar.

10. A suspension device, including in combination a casing, a cross barsecured to said casing, a spring-actuated winding drum, and a tubeconstituting the axis of said drum. and supported at its respective endsby the casing and the cross bar.

, 11. A suspension device, including in combination a support, a windingdrum and a tubular axis therefor, said axis constituting a sleeve for anattaching screw and being fixed in said support without the aid of theattaching screw.`

12. An extension iixture device having a support, a tube constituting anaXis for a winding drum and an attaching screw extending through saidtube to secure said device to the support, said tube being fixed in saidsupport by means independent of said attaching screw.

13. An extension fixture device, having a casing, a chain winding drumwithin and sustained by said casing and an attaching screw extendingthrough said drum to attach the device to a support.

14:. An extension lixture device, including a spring-actuated conicalchain winding drum, said drum having a cap provided with perforationsadapted to be engaged by oppositely acting pawls.

15. A suspension device, including in combination a casing, a cross barsecured thereto, a conical winding drum, an aXis and chain guides, saidaxis and chain guides being carried by said cross bar. p

16. A suspension device, including a drum having a truncated conicalform and a cap `for said drum, said cap having a plurality of detentopenings and tongues formed of metal punched from said openings andextending to and secured in a wall of the drum.

17. A suspension device, having a shell provided with an annular groovein the bottom thereof, a top portion, and a tubular axis resting at itslower end in said groove and secured at its upper end to said topportion.

18. A suspension device, including a winding drum, and a tubular axis,said axis being formed from a single piece of sheet metal the edges ofwhich are secured together by a tongue and a slit, portions of saidedges being spaced for the reception of the end of a coiled spring.

19. A winding drum of conical form, having at its smaller end outwardlyextending lugs punched from the outer wall thereof.

20. A spring actuated suspension device, including in-coinbination adrum, a cap `for said drum having integral punched ton es extending toand secured to the bottom of said drum, a slitted tubular axis and aspring for said drum secured at one end in the slit of said axis andsecured at the other end to one of said tongues.

21. A suspension device, including in combination a shell, a cross-barsecured to said shell, and a tubular axis and idler pulleys supported bysaid cross-bar.

22. A suspension device, including a shell having a cross bar, a windingdrum mounted within said shell and having a series of detent openings inits top, oppositely disposed pawls supported by said cross bar andadapted to singly and successively engage said detent openings.

23. A spring actuated suspension device, including` in combination ashell, a cross-bar supported by said shell, a Winding drum Within saidshell, a spring for actuating Said drum andoppositely disposed clutchesfor controlling reverse movements of said drum, the several parts beingformed from sheet metal and provided with suitable integral securing`lugs and With openings for tlie reception of said securing lugs.

24C. A springactuated suspension device, including in combination ashell of circular 1forni` having diametrically vdisposed lobes,

,said drum and extending over said idlers,

the idlers being so disposed that thechains, when being coiled, willslip i toward the small end of saidwindingdrum and be laid in contact`with each other.

In testimony whereof, We hereunto setour hands this 3rd dayof June,A. D.1918. CORTLAND WV DAVIS. .FRANK R.` VSUNDERLI-N. Witnesses:

V; S. y.JoHNso1\r, H. M. JUNKER.

